Oral Food Challenges
A total of 17 OFCs were performed, of which 15 were conducted to
diagnose secondary nut allergy, with non-culprit nuts, and 2 to clarify
index reactions to a specific nut. Of the first 15 OFCs, 9 were
performed to other nut to which patients were sensitized, but not
exposed to before, all of them with negative or low levels of sIgE
(<2 kU/L) to the respective nut. In the remaining 6 OFCs,
patients had negative skin tests/sIgE and an OFC was performed to
confirm non-allergy and safety in nut introduction. Six (35%) OFCs were
positive (4 with non-culprit nuts and 2 with the suspected nut). All
these patients had mild cutaneous reactions (2 pruritus, without
lesions, and 4 urticaria), 4 of them with spontaneous resolution. The
remaining 2 had symptoms resolution after treatment with oral
antihistamines.